High-grade austenitic stainless steels with a high amount of molybdenum, nickel and copper are suitable for applications in sea water environments, as well as for guiding aggressive chlorine containing media.
In order to manufacture tubes of such stainless steel materials the semi-finished product, namely the hollow, is formed into a tube with defined outer and inner diameters by cold forming. However, cold forming in particular leads to a significant increase of the hardness of the tube.
In order to be able to use these tubes for the above applications they must be shipped as seamless tubes with length of the strand of 6 m or more, which complicates handling during packaging, transporting and further processing.
Furthermore, further processing, in particular for application in the off-shore field, typically requires a stranding of the completed stainless tube with other strands to form a coated bundle of tubes. However, this is opposed by the large hardness of a cold formed austenitic stainless steel tube.